Process for the preparation of compounds useful as SGLT inhibitors

A process for the preparation of a compound of formula (I) ** Formula ** in which Ring A and Ring B are one of the following: (1) Ring A is an optionally substituted unsaturated monocyclic heterocyclic ring, and Ring B is an optionally substituted unsaturated monocyclic heterocyclic ring, an optionally substituted unsaturated fused heterobicyclic ring, or an optionally substituted benzene ring; or (2) Ring A is an optionally substituted benzene ring, and Ring B is an optionally substituted unsaturated monocyclic heterocyclic ring, or an optionally substituted unsaturated fused heterobicyclic ring in which Y is linked to the heterocyclic fused heterocyclic ring; or (3) Ring A is an optionally substituted unsaturated fused heterobicyclic ring, in which the sugar fraction X- (sugar) and the fraction -Y- (Ring B) are both in the same heterocyclic ring of the fused heterobicyclic ring, and Ring B is an optionally substituted unsaturated monocyclic heterocyclic ring, an optionally substituted unsaturated fused heterobicyclic ring, or an optionally substituted benzene ring; X is a carbon atom; Y is - (CH2) n-; where n is 1 or 2; provided that in Ring A, X is part of an unsaturated bond; or a pharmaceutically acceptable salt thereof, or a prodrug thereof; that understands